A wave generating apparatus and method is provided in which a controller actuates a plurality of wave generating chambers in sequence using a delay between actuation of each chamber to produce a rideable wave in a pool. Access to cellular communication network resources is provided by dedicating a portion of communication radio resources to emergency response personnel use. The rail includes a U-turn path section. The motion conversion structure can be configured to convert the valve opening input force into motion of the output structure in an output direction that is non-parallel to the input direction. The power supply apparatus and the power supply apparatus for an electric vehicle respectively including: a charging unit; a main power supplying unit; and an auxiliary power supplying unit. The compounds having structure are excellent low-foaming surfactants.